Microphone



y une 8,1926. 1,588,169v

T. W. YCASE MICROPHONE' l Filed-sept. 27', 192:5

u' m Y mm1( UNITED STATES PATENT OFFICE.

Patented June 8, 1926. I y

' THRODORE WILLARD oasis, OF AUBURN, NEW YORmAssIGNOR 'ro OASE RESEARCH LABORATORY INC., OF AUBURN, NEW YORK, A CORPORATION or NEW YOR..

i MIORORHONE.

Application led September V 27, 1 923. Serial No 665,188.

This yinvention relates to certain improve` Figure `5 is a horizontalsection thru tlie ments in method and apparatus for transgas chainberilliistrated in ligurev 4. lating sound wave variations into corre#v The invention, as shown, com rises asubsponding variations of 'an electric'current, stantially `flat disk -1- whic may .per-

lwhich latter variations may be used Or haps preferably be of circular form and is 60 translated' as desired.- Orv perhaps diierprovided with anopening 2-illustrated ently stated,vthe invention relates to a methlin Figures 1, 2 and V3, as of' substantially od or apparatus for producing variations of rectangular form, -ad in'-Figures 2 1 and 5' an electric current in accordance with or, as ofsubstantially circular form, altho the corresponding to sound Wave variations, [opening may be of various'and many forms 6&5

and specifically I 'term the apparatus a gasand I do not, therefore, -restrictlmyself to thermo microphone. any shape, size or form ofopening. The main object of the invention is toy Within this opening is arranged-.ashort produce a highly sensitive instrument 'that wire -Sqformed of a .material that varies Will intensify the sound effect and accuits electrical resistance in accordance with 70 rately translate sound Waves into correits temperature, and theopposite ends: ofl sponding variations of electric current, this wire -3- are'conneoted in circuitwith which latter variations may be re-translated the positive and negative sides respectively with or Without amplification, and with' of a variable source of potential, such as the practically perfect quality. A further and more specific. Object resides known construction beingv provided for in the elimination of distortion and foreign letlecting desired variations of the source of noises vwhich'might result froinsympatlietie potential utilized for heating4 .the wire diaphragm vibrations or other causes, and -3-.^

which effect the sound Waves to be translVithin this circuit may be positionedlthei30.`

f lated or their transmission, and reference is primary #t3-'fof' a transformer, the second-v hereby made to my co-pending application ary `6 of whichmay be connected' to Serial No. 652,281, ledJuly 18, 1928, and suitable amplifying means or directly"y to which describes and'claims the broad sub` any suitable translating means, such'as the vject inatterdisclosed herein, theclaims of telephone receivers -7-. Preferably, the 35 this application being restricted to the ad. Wire 3 is of very small diameter, -as for ditional feature 4of the combination disillustration, plusor minus .00001, and is in closed herein residing in means for varying the form ofa coil or lor;r pitch Spiral, as

and regulating the size of thev Opening or indicated, and is arranged in the, Opening gas passage Ain 'which the element, wire, or -2- in the disk.1, and for illustrative 90 thermo-electric,element which varies its repurposes this .opening 2 may be vabout sistance in accordance with its temperaturel one-halt an -inch long and one-quarter vinch is positioned wherebythe gas current pass Wide,` and the Wire g3- in its spiral form ing thru said opening can be regulated and may be approximately one-quarter inch varied' and the apparatus adjusted to the long so as to fit within the Opening without 95 most satisfactory condition of operation contacttherewith. However, the opening under the existing circumstances. maybe of variousv shapes, as circular, 'and In vthe drawings the Wire instead of being spiral inform may Figure 1 is la diagrammatic illustration be of varied forms,`as straight,'and more;

of the invention with thel gas chamber than one Wire --3- may be used if desired. shown in section. I The disk -.,-1'- may, as shown, beformed Figure 2 is a section on'line 2 2, ,Fig-4 vwith an-annular fiange 8 penetrated by ure 1'. an inlet pipe 9- adapted vto carry la as Figure 3 is a front elevation of the gasdsuch as air, or a combination .of'gases un er '50 chamber. pressure -from any suitable source. ofiA =sup- 105 Figure 4 isya view 'similar to Figure 2, ply, as a blower 10;-, and the rate ofilow but in which the gas chamber has a circular of gas from'the pipe 9'- is adjusted for ,i

opening as distinguished from a somewhat the best sensitivityf'of the ,apparatus and rectangular one, and is taken on line 4 4, may be 'iust below the point where pa-sage Figure 5. of gas through the opening -2- around 1.19

ld i

2i s C 1 i o; aorim such as tuin silk, may los secured acres., lie open. end of the iiangev wrdance vWilli iis einperaure, and -altlio ions sulisancemly be used, I have ouiiid piainunrsuitable for 'the purpose iiacing 'the filament in an opening'oi desired sise, suoli as alle opening -f=-7 in 'fceusiiies lie sou-nd efectresultanr. from 4lie use o the apparatus and Wiiliout distortion. Preferably, the disk -lis 'used as alie iront of apparaiushand .is toward ilsei speaker or 'cheI soun'd`- Waves jwliicli il:l is desired. sfo 'rais'laijeo in" this vposition ille und Waves .tolse translated are coming in a direcision substantially opposite 'to *diel direction or' "the -nioveinen'fefftlic gas escaping lirougli ille opening,-2-,and act@ to `cool ilie `spiral Wire 3- sisioningyoi? the instrumenc ifc, however, essential eltlio in v present experience leads me so lleiieve theta-more advantageous 'resullo'bained in, 'iliat' manner.'

have loundlha ii. is very desirable and advantagcousjin `an apparatus of this' racero provide ineens 'for readily and varying 'die size oitlie opening -2- .L Viiicl'i the resistance'element S5- is po-v iioned, and in Figures 2 and 3i have illustratcd for this purpose slides or' plates @-43- 'and -14% posiiioned'upon opposite sides o'f *che opening -`-2L, and slidable acrosstlie opening torestrictor enlarge its as may .be cl'esired Thesev slides or shuers maybe supporjtvedinfany suitable' way ior adjusn'ieni, as" described, and for:

'that purpose i llieve slio'n tlicin carried and supported by sind -15-' and 16- 'for' engagement .with loclingfnuts -19- an'd -20- respectively 'lor securing the slides in any desired.position of adjustment `for producing the desired arca olf opening.

shown, arc guided in channel, ways formed o lie passage of anelectric cu'iien'ain acA so 'llia when the shutters are adjesi'ed in one 7 relative `position 'they form a snbszurtislly circular opening.) lie size of wliicli can be varied by sliding i-lie shutters eitherioward or from eacli other and for itliispiei'pose 'the adjacent Aends of ille sluitt'e'rs have a portion Aof tlieirjthickness out away 'sorbet one may slide upon the einer. ln other Words, the inner endg of the shutters and 9.6M .are eacl'i preferably'o' substantially onefhalf the thickness of the body of the shutter, as :illustrated zii- 27W and m28-4", and' tls parte are oppositely disposed so chat o may slide upon the .einer and jointly the; constitute la thickness substantially equal io the thiclmessofthe cody 'of 'either'o the shutters r-2-5- .and 2G-4. bviously, relfative. sliding movements of the plaies' -w-u and -26- will vary somewlia the shape of the opening #2f from an exact circular ormand the structure l". have 'shown i" purely illustrative of 'a 'meansfforfvaryi the size of an openingl which at'one par Jcicular adjustment is circular, andvarious and many other structures may" be substituted for tliabishown, and. Well known con 95 siructions-.sucli as a camera sliuter con* struction rcavbeuuiiiized 'Eoiadjusiing the size of the opening' '-2-, thev structures that have `shown being' 'purely illustrative ci means for accomplishing this desiralole relo@ (lll a gas `clianaloe'r means for supplying gas 1 under pressure to said, clianoloel"` an outlei. from said chamber, a member which Varies its electrical conductivity in accordance with' its temperature exposed to die gas'escaping through said openingV means i'orfl'ieating; said nicnibcr, and means for 'varying the area of said passageway .to tlierebyvary the crosssectional area oi 't-lrc stream oil gas 'escaping thru saidv outlet. "l

Q. In an apparatus of flie combination.with a passageway for av forced current of gas, of a linciiber exposed to the gasescaping through said passa-gewajv3 means ior hearing said member; and means for varying flic area ol said passageway.

3. In an apparaiusfoi' tlie class described, the combination with a passageway for a ,lorccd currcnioi gas of a mein'ber which iarirs its electrical conductivity in accordance willi its einpcralgure exposed lio the gas V'ille class described, 1m

escaping through said opening, means for. Aheating said -member and means for varying under pressure to'said chamber, a passagewaythrough a wall of said chamber and constituting an outlet from the chamber, a member that varies its electrical conductivity in accordance with its temperature arranged so as to be exposed to the as escaping through said outlet, a source og potential in circnt'with said member for heating the latter, and means for Varying the area of said passageway.

5. In an apparatus of the class described, a

gas chamber, means for supplying gas under, pressure 'to said chamber, an outlet from said chamber, a member which varies its electrical conductivity in acordance with its temperature exposed to the gas escaping through said'opening, means for heating said y member, means for varying the area of said passageway to thereby vary the cross-sectional area of, the stream of gas escapin thru said outlet', and said chamber forme with a porous wall. In witness whereof I have hereunto set my hand this 6th day of September, 1923; -THEODOR'E lWILLARDl CASE. 

